In the copending parent patent application Ser. No. 07/906,573, filed Jun. 30, 1992, small articles such as dry cell batteries, lipstick containers, lip balm containers and the like are labeled with high quality, thin film polymeric labels. An adhesive is applied by printing onto an area adjacent the leading edge of the label and a predetermined amount of solvent is evenly applied onto the area adjacent the trailing edge of the label. The articles are wrapped, securing first the leading edge, followed by overlapping the trailing edge onto the leading edge. The articles having wrapped labels applied thereto are then heated. The apparatus provides for high quality cylindrical labeling of small articles such as dry cell batteries using thin film, polymeric labels, e.g., typically less than 0.0035 inches thickness.
Beneficial solvent application is obtained when a pattern of solvent is applied to the label by the use of a rotating wiper tip which holds the solvent captive on the edge of the flexible wiper tip. In one disclosed embodiment of the invention, the wiper tip includes a V-notch for holding captive the solvent. As the wiper tip moves at the same surface speed as the label transport drum, the wiper tip is deflected against the trailing edge of the label, and the solvent is evenly transferred to the label. In another embodiment, a flexible, tapered tip evenly applies solvent onto the label when the surface speed of the wiper tip is different from the surface speed of the label and drum.
In one embodiment, the speed differential between the wiper tip and the label causes application of a "bead" of solvent at the point of departure of the wiper from the label, at a point adjacent to, but spaced from the trailing edge of the label. When the wiper moves slower then the surface speed of the label transport drum, the solvent is wiped toward the trailing edge of the label. If the wiper tip is moving faster than the surface speed of the label transport drum, the solvent is wiped from the trailing edge of the label forward. As the article rolls back over the solvent during wrapping, the weight of the article pushes the solvent evenly across the pretreated area on which the solvent was applied onto the trailing edge, thus in essence obtaining a more even solvent wipe along the trailing edge of the label.
This high quality labeling of small articles, such as dry cell batteries requires precision labeling without mismatching the label ends as the article is wrapped. Such mismatching can occur if the label is skewed relative to the article during wrapping. For example, the labels often have printed matter with colored vertical zones, lettering and other associated trade logos that must align and match when the seam is formed between leading and trailing edges. Any label mismatch between leading and trailing edges would be unacceptable.
It has been found that wrap around labeling as heretofore described sometimes mismatches smaller labels as they are wrapped onto smaller cylindrical articles at high operating speeds. The physical dynamics of wrapping these smaller cylindrical articles with a small label makes control over such processes difficult without adequate means for ensuring correct alignment and matching of label ends during wrapping. Such article alignment means not only should compensate for different article and label sizes but also should compensate for production exigencies as they arise.